Force arrester



Sept. 15, 1970 E. H. EASTlN FORCE ARRESTER Filed Oct. 6, 1967 INVENTOR.

-M L12M United States Patent Ofiice 3,528,650 Patented Sept. 15, 1970 3,528,650 FORCE ARRESTER Edward H. Eastin, 254 Reitmau Court, Rochester, Mich. 48063 Filed Oct. 6, 1967, Ser. No. 673,377 Int. Cl. F16f 3/07 US. Cl. 267-64 13 Claims ABSTRACT OF THE DISCLOSURE The force arrester disclosed herein comprises a cylinder which has a piston reciprocally mounted therein and a piston shaft fixed to the piston extending through one flexible end of the cylinder. A carrier having a plurality of closure members is interposed between the other end of said cylinder and said piston. The closure members on the carrier are adapted to progressively engage axial openings in the piston to variably restrict the flow of fluid through the axial passages when the piston shaft is engaged by a force to move the piston in one direction.

BACKGROUND OF THE INVENTION This invention relates to a force arrester and particularly to a fluid force arrester for engaging and interrupting the movement of an object which is moving with substantial force.

In machine tools and the like, wherein parts are moved at rapid rates, it is desirable to provide some means for stopping the parts smoothly and quickly.

Among the objects of the invention are to provide a force arrester of the fluid type which efliciently absorbs the force of movement of a part; which is simple, easy to maintain and low in cost.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a part sectional view of a force arrester embodying the invention.

FIG. 2 is a fragmentary sectional view taken along the line 2-2 in FIG. 1.

FIG. 3 is a fragmentary sectional view similar to FIG. 1 showing the parts in a different operative position.

DESCRIPTION Referring to FIG. 1, the force arrester embodying the invention comprises a cylinder that has one rigid end 11 and an opposite end formed by a flexible diaphragm 12 which has its outer extremity 13 flexed over the end of the cylinder wall and held in position by a clamping beand 14. A piston 15 which has substantial axial extent is reciprocably mounted in the cylinder and has an integral piston shaft 16. Diaphragm 12 has its inner end clamped to piston shaft 16 by a band 16a. The axial extent of the piston 15 which engages the inner wall of the cylinder is substantial so that the piston shaft 16 is rigidly held against lateral movement even though there is no outboard bearings therefor. A returning ring 16b limits the outward movement of piston 16.

The piston 15 has a plurality of circumferentially when the carrier is compressed. An adjusting shaft 23 is fixed to the disc 21 and extends through an axial opening 24 in the piston shaft 1 6. A cross pin 25 in the upper end of the adjusting shaft 23 extends radially and into a collar 26 surrounding the upper end of the shaft 16. O-rings 27 frictionally hold the collar 26 in position. The upper end of the carrier 18 extends through the adjusting shaft 23 as at 28. By rotating the collar 26, the registry of the openings 22 and disc 21 with the axial passages 17 may be varied to vary the effective size of the axial passages in the piston. A resilient bumper pad 30 is provided on the upper end of the piston shaft 16. a

The carrier and closure members may have other forms as disclosed in my copending application Ser. No. 659,364, filed Aug. 9, 1967.

In use, the force arrester is provided adjacent a part or tool in position so that as the tool approaches the end of its movement, it will engage the bumper pad 30 and move the piston 15 axially of the cylinder. As the piston 15 is moved axially to the position shown, for example, in FIG. 3, the carrier is compressed and balls 20 are progressively brought into engagement with the openings 22 to restrict the flow of fluid from the lower end of the piston to the upper end of the piston. The flexible end .wall 12 provides a variable chamber for the flow of fluid above the piston. When the part or tool is retracted, the carrier 18 returns the piston 15 to its original position.

By rotating disc 21 the effective size of axial passages 17 can be varied to vary the rate of arrest of the force.

I claim:

1. In a fluid actuator, the combination comprising a cylinder,

8. piston mounted for reciprocating movement within said cylinder,

2. piston shaft fixed to said cylinder and projecting beyond one end of said cylinder,

said piston defining two chambers within said cylinder,

said piston having a plurality of axially extending openings therethrough,

a carrier interposed between the other end of said piston opposite said piston shaft and the other end of said cylinder,

closure means on said carrier operable consecutively and progressively to restrict flow through said axial passages as the piston is moved inwardly of the cylinder,

said piston shaft having means on the free end thereof for engagement with a body to move said piston to produce a force restricting effect.

2. The combination set forth in claim 1 including flexible means closing said one end of said cylinder and providing a variable size chamber between said end and 'said piston.

3. The combination set forth in claim 1 wherein said carrier comprises a spiral spring,

said spring being operable to return said piston to its origina lposition after arresting a force.

4.- The combination set forth in claim 3 wherein said closure means comprises balls on said spring.

5. The combination set forth in claim 1 including a flexible diaphragm closing said one end of said cylinder,

said piston having substantial longitudinal extent to provide lateral stability to said piston and piston shaft.

' 6. The combination set forth in claim 1 including means for varying the size of the axial passages in said piston.

7. The combination set forth in claim 6 wherein said last-mentioned means comprises a disc adjacent said piston having openings therein,

said disc with the axialpassages insa-id'piston."

8. The combination set forth in claim 7 wherein said last-mentioned means comprises an adjusting shaft,

said piston shaft having an ,axial opening therein through which said adjusting shaft extends,

means connecting said adjusting shaft to said disc,

and means externally of said piston shaft and operatively connected to said adjusting shaft for rotating said adjusting shaft relative to said piston shaft.

9. The combination set forth in claim 1 wherein said carrier has one end thereof fixed to said piston.

10. In a fluid actuator, the combination comprising a cylinder,

a piston mounted for reciprocating movement within said cylinder,

a piston shaft fixed to said cylinder and projecting beyond one end of said cylinder,

said piston defining two chambers within said cylinder,

said piston having a plurality of axially extending openings therethrough, a carrier interposed between the other end of said piston opposite said piston shaft and the other end of said' for engagement with a body to move said piston to produce a force restricting'effect,

a flexible end wall closing said one end of said cylinder,

said piston having substantial longitudinal extent to provide lateral stability to said piston and piston shaft.

11. The combination set forth in claim 10 including means for varying the size of the axial passages in said piston.

12. The combination set forth in claim 11 wherein said last-mentioned means comprises a disc adjacent said piston having openings therein,

a means for varying the registry of the openings in said disc 'with the axial passages in said piston.

13.. The combination set forth in claim 12 wherein said last-mentioned means comprises anadjusting shaft,

said piston shaft having an axial opening therein through which said adjusting shaft extends, v means connecting said adjusting shaft to said disc, and means externally of said piston shaft and operatively connected to said adjusting shaft for rotating said adjusting shaft relative to said piston shaft.

References Cited UNITED STATES PATENTS 3,033,554 5/1962 Francis 26734 3,276,763 10/1966 Blatt 267l 3,361,422 1/1968 Theuleau 267-64 JAMES B. MARBERT, Primary Examiner US. Cl. X.R. 

